The present invention relates to a fixing device, and particularly to a fixing device for attaching a heat sink to a CPU package, supporting the heat sink on a circuit board and preventing vibration of the heat sink during operation.
During operation of a computer, excessive heat is generated by electrical elements thereof. Since the processing speed of a CPU is increasing, more heat is generated. Thus, cooling the CPU package is an important consideration facing computer designers. Generally, a heat sink is employed to dissipate heat generated by the CPU package. The more heat generated, the larger the heat sink required. A fixing device is commonly used to attach the heat sink to the CPU package, support the heat sink on a circuit board and prevent vibration of the heat sink during operation.
A conventional fixing device comprises a first locking member, a second locking member and a pair of locking nuts. Generally, a pair of positioning posts is formed on a bottom surface of the second locking member, and the conventional positioning post is hollow. Each positioning post has a uniform inner diameter and engages a corresponding locking hole of a circuit board. The positioning post cannot provide adequate interference with the locking hole when engaging with a locking nut. Thus, vibration of the heat sink results during operation.
Thus, there is a need for an improved fixing device for reliably attaching a heat sink to a CPU package.